[mirror_frr.git] / bgpd / bgp_conditional_adv.c

/*
 * BGP Conditional advertisement
 * Copyright (C) 2020  Samsung R&D Institute India - Bangalore.
 *			Madhurilatha Kuruganti
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "bgpd/bgp_conditional_adv.h"

const char *get_afi_safi_str(afi_t afi, safi_t safi, bool for_json);

static route_map_result_t
bgp_check_rmap_prefixes_in_bgp_table(struct bgp_table *table,
				     struct route_map *rmap)
{
	struct attr dummy_attr = {0};
	struct bgp_dest *dest;
	struct bgp_path_info *pi;
	struct bgp_path_info path = {0};
	struct bgp_path_info_extra path_extra = {0};
	const struct prefix *dest_p;
	route_map_result_t ret = RMAP_DENYMATCH;

	for (dest = bgp_table_top(table); dest; dest = bgp_route_next(dest)) {
		dest_p = bgp_dest_get_prefix(dest);
		assert(dest_p);

		for (pi = bgp_dest_get_bgp_path_info(dest); pi; pi = pi->next) {
			dummy_attr = *pi->attr;

			/* Fill temp path_info */
			prep_for_rmap_apply(&path, &path_extra, dest, pi,
					    pi->peer, &dummy_attr);

			RESET_FLAG(dummy_attr.rmap_change_flags);

			ret = route_map_apply(rmap, dest_p, &path);
			if (ret != RMAP_PERMITMATCH)
				bgp_attr_flush(&dummy_attr);
			else {
				bgp_dest_unlock_node(dest);
				if (BGP_DEBUG(update, UPDATE_OUT))
					zlog_debug(
						"%s: Condition map routes present in BGP table",
						__func__);

				return ret;
			}
		}
	}

	if (BGP_DEBUG(update, UPDATE_OUT))
		zlog_debug("%s: Condition map routes not present in BGP table",
			   __func__);

	return ret;
}

static void bgp_conditional_adv_routes(struct peer *peer, afi_t afi,
				       safi_t safi, struct bgp_table *table,
				       struct route_map *rmap,
				       enum update_type update_type)
{
	int addpath_capable;
	struct bgp_dest *dest;
	struct bgp_path_info *pi;
	struct bgp_path_info path;
	struct peer_af *paf;
	const struct prefix *dest_p;
	struct update_subgroup *subgrp;
	struct attr dummy_attr = {0}, attr = {0};
	struct bgp_path_info_extra path_extra = {0};

	paf = peer_af_find(peer, afi, safi);
	if (!paf)
		return;

	subgrp = PAF_SUBGRP(paf);
	/* Ignore if subgroup doesn't exist (implies AF is not negotiated) */
	if (!subgrp)
		return;

	if (BGP_DEBUG(update, UPDATE_OUT))
		zlog_debug("%s: %s routes to/from %s for %s", __func__,
			   update_type == ADVERTISE ? "Advertise" : "Withdraw",
			   peer->host, get_afi_safi_str(afi, safi, false));

	addpath_capable = bgp_addpath_encode_tx(peer, afi, safi);

	for (dest = bgp_table_top(table); dest; dest = bgp_route_next(dest)) {
		dest_p = bgp_dest_get_prefix(dest);
		assert(dest_p);

		for (pi = bgp_dest_get_bgp_path_info(dest); pi; pi = pi->next) {
			dummy_attr = *pi->attr;

			/* Fill temp path_info */
			prep_for_rmap_apply(&path, &path_extra, dest, pi,
					    pi->peer, &dummy_attr);

			RESET_FLAG(dummy_attr.rmap_change_flags);

			if (route_map_apply(rmap, dest_p, &path)
			    != RMAP_PERMITMATCH) {
				bgp_attr_flush(&dummy_attr);
				continue;
			}

			if (CHECK_FLAG(pi->flags, BGP_PATH_SELECTED)
			    || (addpath_capable
				&& bgp_addpath_tx_path(
					   peer->addpath_type[afi][safi],
					   pi))) {

				/* Skip route-map checks in
				 * subgroup_announce_check while executing from
				 * the conditional advertise scanner process.
				 * otherwise when route-map is also configured
				 * on same peer, routes in advertise-map may not
				 * be advertised as expected.
				 */
				if ((update_type == ADVERTISE)
				    && subgroup_announce_check(dest, pi, subgrp,
							       dest_p, &attr,
							       true))
					bgp_adj_out_set_subgroup(dest, subgrp,
								 &attr, pi);
				else {
					/* If default originate is enabled for
					 * the peer, do not send explicit
					 * withdraw. This will prevent deletion
					 * of default route advertised through
					 * default originate.
					 */
					if (CHECK_FLAG(
						    peer->af_flags[afi][safi],
						    PEER_FLAG_DEFAULT_ORIGINATE)
					    && is_default_prefix(dest_p))
						break;

					bgp_adj_out_unset_subgroup(
						dest, subgrp, 1,
						bgp_addpath_id_for_peer(
							peer, afi, safi,
							&pi->tx_addpath));
				}
			}
		}
	}
}

/* Handler of conditional advertisement timer event.
 * Each route in the condition-map is evaluated.
 */
static int bgp_conditional_adv_timer(struct thread *t)
{
	afi_t afi;
	safi_t safi;
	int pfx_rcd_safi;
	struct bgp *bgp = NULL;
	struct peer *peer = NULL;
	struct peer_af *paf = NULL;
	struct bgp_table *table = NULL;
	struct bgp_filter *filter = NULL;
	struct listnode *node, *nnode = NULL;
	struct update_subgroup *subgrp = NULL;
	route_map_result_t ret;

	bgp = THREAD_ARG(t);
	assert(bgp);

	thread_add_timer(bm->master, bgp_conditional_adv_timer, bgp,
			 CONDITIONAL_ROUTES_POLL_TIME, &bgp->t_condition_check);

	/* loop through each peer and advertise or withdraw routes if
	 * advertise-map is configured and prefix(es) in condition-map
	 * does exist(exist-map)/not exist(non-exist-map) in BGP table
	 * based on condition(exist-map or non-exist map)
	 */
	for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
		if (!CHECK_FLAG(peer->flags, PEER_FLAG_CONFIG_NODE))
			continue;

		if (peer->status != Established)
			continue;

		FOREACH_AFI_SAFI (afi, safi) {
			if (strmatch(get_afi_safi_str(afi, safi, true),
				     "Unknown"))
				continue;

			if (!peer->afc_nego[afi][safi])
				continue;

			/* labeled-unicast routes are installed in the unicast
			 * table so in order to display the correct PfxRcd value
			 * we must look at SAFI_UNICAST
			 */
			pfx_rcd_safi = (safi == SAFI_LABELED_UNICAST)
					       ? SAFI_UNICAST
					       : safi;

			table = bgp->rib[afi][pfx_rcd_safi];
			if (!table)
				continue;

			filter = &peer->filter[afi][safi];

			if (!filter->advmap.aname || !filter->advmap.cname
			    || !filter->advmap.amap || !filter->advmap.cmap)
				continue;

			if (!peer->advmap_config_change[afi][safi]
			    && !peer->advmap_table_change)
				continue;

			if (BGP_DEBUG(update, UPDATE_OUT)) {
				if (peer->advmap_table_change)
					zlog_debug(
						"%s: %s - routes changed in BGP table.",
						__func__, peer->host);
				if (peer->advmap_config_change[afi][safi])
					zlog_debug(
						"%s: %s for %s - advertise/condition map configuration is changed.",
						__func__, peer->host,
						get_afi_safi_str(afi, safi,
								 false));
			}

			/* cmap (route-map attached to exist-map or
			 * non-exist-map) map validation
			 */
			ret = bgp_check_rmap_prefixes_in_bgp_table(
				table, filter->advmap.cmap);

			/* Derive conditional advertisement status from
			 * condition and return value of condition-map
			 * validation.
			 */
			if (filter->advmap.condition == CONDITION_EXIST)
				filter->advmap.update_type =
					(ret == RMAP_PERMITMATCH) ? ADVERTISE
								  : WITHDRAW;
			else
				filter->advmap.update_type =
					(ret == RMAP_PERMITMATCH) ? WITHDRAW
								  : ADVERTISE;

			/* Send regular update as per the existing policy.
			 * There is a change in route-map, match-rule, ACLs,
			 * or route-map filter configuration on the same peer.
			 */
			if (peer->advmap_config_change[afi][safi]) {

				if (BGP_DEBUG(update, UPDATE_OUT))
					zlog_debug(
						"%s: Configuration is changed on peer %s for %s, send the normal update first.",
						__func__, peer->host,
						get_afi_safi_str(afi, safi,
								 false));

				paf = peer_af_find(peer, afi, safi);
				if (paf) {
					update_subgroup_split_peer(paf, NULL);
					subgrp = paf->subgroup;
					if (subgrp && subgrp->update_group)
						subgroup_announce_table(
							paf->subgroup, NULL);
				}
				peer->advmap_config_change[afi][safi] = false;
			}

			/* Send update as per the conditional advertisement */
			bgp_conditional_adv_routes(peer, afi, safi, table,
						   filter->advmap.amap,
						   filter->advmap.update_type);
		}
		peer->advmap_table_change = false;
	}
	return 0;
}

void bgp_conditional_adv_enable(struct peer *peer, afi_t afi, safi_t safi)
{
	struct bgp *bgp = peer->bgp;

	assert(bgp);

	/* This flag is used to monitor conditional routes status in BGP table,
	 * and advertise/withdraw routes only when there is a change in BGP
	 * table w.r.t conditional routes
	 */
	peer->advmap_config_change[afi][safi] = true;

	/* advertise-map is already configured on atleast one of its
	 * neighbors (AFI/SAFI). So just increment the counter.
	 */
	if (++bgp->condition_filter_count > 1) {
		if (BGP_DEBUG(update, UPDATE_OUT))
			zlog_debug("%s: condition_filter_count %d", __func__,
				   bgp->condition_filter_count);

		return;
	}

	/* Register for conditional routes polling timer */
	thread_add_timer(bm->master, bgp_conditional_adv_timer, bgp,
			 CONDITIONAL_ROUTES_POLL_TIME, &bgp->t_condition_check);
}

void bgp_conditional_adv_disable(struct peer *peer, afi_t afi, safi_t safi)
{
	struct bgp *bgp = peer->bgp;

	assert(bgp);

	/* advertise-map is not configured on any of its neighbors or
	 * it is configured on more than one neighbor(AFI/SAFI).
	 * So there's nothing to do except decrementing the counter.
	 */
	if (--bgp->condition_filter_count != 0) {
		if (BGP_DEBUG(update, UPDATE_OUT))
			zlog_debug("%s: condition_filter_count %d", __func__,
				   bgp->condition_filter_count);

		return;
	}

	/* Last filter removed. So cancel conditional routes polling thread. */
	THREAD_OFF(bgp->t_condition_check);
}
Commit	Line	Data
7f7940e6 MK	1	/*
7f7940e6 MK	2	* BGP Conditional advertisement
1a0416bd	3	* Copyright (C) 2020 Samsung R&D Institute India - Bangalore.
7f7940e6 MK	4	* Madhurilatha Kuruganti
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the Free
	8	* Software Foundation; either version 2 of the License, or (at your option)
	9	* any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful, but WITHOUT
	12	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	13	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	14	* more details.
	15	*
	16	* You should have received a copy of the GNU General Public License along
	17	* with this program; see the file COPYING; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	19	*/
	20
	21	#include "bgpd/bgp_conditional_adv.h"
	22
	23	const char *get_afi_safi_str(afi_t afi, safi_t safi, bool for_json);
	24
c385f82a	25	static route_map_result_t
7f7940e6 MK	26	bgp_check_rmap_prefixes_in_bgp_table(struct bgp_table *table,
	27	struct route_map *rmap)
	28	{
52b84062	29	struct attr dummy_attr = {0};
c385f82a	30	struct bgp_dest *dest;
c385f82a	31	struct bgp_path_info *pi;
52b84062 MK	32	struct bgp_path_info path = {0};
	33	struct bgp_path_info_extra path_extra = {0};
	34	const struct prefix *dest_p;
	35	route_map_result_t ret = RMAP_DENYMATCH;
c385f82a MK	36
	37	for (dest = bgp_table_top(table); dest; dest = bgp_route_next(dest)) {
	38	dest_p = bgp_dest_get_prefix(dest);
52b84062	39	assert(dest_p);
7f7940e6	40
c385f82a MK	41	for (pi = bgp_dest_get_bgp_path_info(dest); pi; pi = pi->next) {
c385f82a MK	42	dummy_attr = *pi->attr;
52b84062 MK	43
	44	/* Fill temp path_info */
	45	prep_for_rmap_apply(&path, &path_extra, dest, pi,
	46	pi->peer, &dummy_attr);
	47
	48	RESET_FLAG(dummy_attr.rmap_change_flags);
7f7940e6	49
1782514f	50	ret = route_map_apply(rmap, dest_p, &path);
52b84062 MK	51	if (ret != RMAP_PERMITMATCH)
52b84062 MK	52	bgp_attr_flush(&dummy_attr);
e73c112e	53	else {
dc52bece	54	bgp_dest_unlock_node(dest);
e73c112e MK	55	if (BGP_DEBUG(update, UPDATE_OUT))
	56	zlog_debug(
	57	"%s: Condition map routes present in BGP table",
	58	__func__);
	59
c385f82a	60	return ret;
e73c112e	61	}
7f7940e6	62	}
7f7940e6	63	}
e73c112e MK	64
	65	if (BGP_DEBUG(update, UPDATE_OUT))
	66	zlog_debug("%s: Condition map routes not present in BGP table",
	67	__func__);
	68
7f7940e6 MK	69	return ret;
	70	}
	71
c385f82a MK	72	static void bgp_conditional_adv_routes(struct peer *peer, afi_t afi,
	73	safi_t safi, struct bgp_table *table,
	74	struct route_map *rmap,
e73c112e	75	enum update_type update_type)
7f7940e6 MK	76	{
7f7940e6 MK	77	int addpath_capable;
52b84062	78	struct bgp_dest *dest;
c385f82a	79	struct bgp_path_info *pi;
52b84062 MK	80	struct bgp_path_info path;
	81	struct peer_af *paf;
	82	const struct prefix *dest_p;
	83	struct update_subgroup *subgrp;
	84	struct attr dummy_attr = {0}, attr = {0};
	85	struct bgp_path_info_extra path_extra = {0};
7f7940e6 MK	86
	87	paf = peer_af_find(peer, afi, safi);
	88	if (!paf)
c385f82a	89	return;
7f7940e6 MK	90
	91	subgrp = PAF_SUBGRP(paf);
	92	/* Ignore if subgroup doesn't exist (implies AF is not negotiated) */
	93	if (!subgrp)
c385f82a	94	return;
7f7940e6	95
e73c112e MK	96	if (BGP_DEBUG(update, UPDATE_OUT))
	97	zlog_debug("%s: %s routes to/from %s for %s", __func__,
	98	update_type == ADVERTISE ? "Advertise" : "Withdraw",
	99	peer->host, get_afi_safi_str(afi, safi, false));
	100
7f7940e6 MK	101	addpath_capable = bgp_addpath_encode_tx(peer, afi, safi);
7f7940e6 MK	102
c385f82a MK	103	for (dest = bgp_table_top(table); dest; dest = bgp_route_next(dest)) {
c385f82a MK	104	dest_p = bgp_dest_get_prefix(dest);
52b84062	105	assert(dest_p);
7f7940e6	106
c385f82a MK	107	for (pi = bgp_dest_get_bgp_path_info(dest); pi; pi = pi->next) {
c385f82a MK	108	dummy_attr = *pi->attr;
52b84062 MK	109
	110	/* Fill temp path_info */
	111	prep_for_rmap_apply(&path, &path_extra, dest, pi,
	112	pi->peer, &dummy_attr);
	113
	114	RESET_FLAG(dummy_attr.rmap_change_flags);
7f7940e6	115
1782514f	116	if (route_map_apply(rmap, dest_p, &path)
52b84062 MK	117	!= RMAP_PERMITMATCH) {
52b84062 MK	118	bgp_attr_flush(&dummy_attr);
7f7940e6	119	continue;
52b84062	120	}
7f7940e6	121
c385f82a MK	122	if (CHECK_FLAG(pi->flags, BGP_PATH_SELECTED)
	123	\|\| (addpath_capable
	124	&& bgp_addpath_tx_path(
	125	peer->addpath_type[afi][safi],
	126	pi))) {
	127
	128	/* Skip route-map checks in
	129	* subgroup_announce_check while executing from
	130	* the conditional advertise scanner process.
	131	* otherwise when route-map is also configured
	132	* on same peer, routes in advertise-map may not
	133	* be advertised as expected.
	134	*/
e73c112e	135	if ((update_type == ADVERTISE)
c385f82a MK	136	&& subgroup_announce_check(dest, pi, subgrp,
	137	dest_p, &attr,
	138	true))
	139	bgp_adj_out_set_subgroup(dest, subgrp,
	140	&attr, pi);
	141	else {
	142	/* If default originate is enabled for
	143	* the peer, do not send explicit
	144	* withdraw. This will prevent deletion
	145	* of default route advertised through
	146	* default originate.
	147	*/
	148	if (CHECK_FLAG(
	149	peer->af_flags[afi][safi],
	150	PEER_FLAG_DEFAULT_ORIGINATE)
	151	&& is_default_prefix(dest_p))
	152	break;
	153
	154	bgp_adj_out_unset_subgroup(
	155	dest, subgrp, 1,
	156	bgp_addpath_id_for_peer(
	157	peer, afi, safi,
	158	&pi->tx_addpath));
	159	}
	160	}
7f7940e6 MK	161	}
7f7940e6 MK	162	}
7f7940e6 MK	163	}
	164
	165	/* Handler of conditional advertisement timer event.
	166	* Each route in the condition-map is evaluated.
	167	*/
	168	static int bgp_conditional_adv_timer(struct thread *t)
	169	{
	170	afi_t afi;
	171	safi_t safi;
	172	int pfx_rcd_safi;
	173	struct bgp *bgp = NULL;
	174	struct peer *peer = NULL;
	175	struct peer_af *paf = NULL;
	176	struct bgp_table *table = NULL;
	177	struct bgp_filter *filter = NULL;
	178	struct listnode node, nnode = NULL;
	179	struct update_subgroup *subgrp = NULL;
c385f82a	180	route_map_result_t ret;
7f7940e6 MK	181
	182	bgp = THREAD_ARG(t);
	183	assert(bgp);
	184
7f7940e6 MK	185	thread_add_timer(bm->master, bgp_conditional_adv_timer, bgp,
	186	CONDITIONAL_ROUTES_POLL_TIME, &bgp->t_condition_check);
	187
	188	/* loop through each peer and advertise or withdraw routes if
	189	* advertise-map is configured and prefix(es) in condition-map
c385f82a MK	190	* does exist(exist-map)/not exist(non-exist-map) in BGP table
c385f82a MK	191	* based on condition(exist-map or non-exist map)
7f7940e6	192	*/
c385f82a MK	193	for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
c385f82a MK	194	if (!CHECK_FLAG(peer->flags, PEER_FLAG_CONFIG_NODE))
7f7940e6 MK	195	continue;
7f7940e6 MK	196
52b84062 MK	197	if (peer->status != Established)
	198	continue;
	199
c385f82a MK	200	FOREACH_AFI_SAFI (afi, safi) {
	201	if (strmatch(get_afi_safi_str(afi, safi, true),
	202	"Unknown"))
7f7940e6	203	continue;
c385f82a	204
52b84062	205	if (!peer->afc_nego[afi][safi])
7f7940e6 MK	206	continue;
7f7940e6 MK	207
c385f82a MK	208	/* labeled-unicast routes are installed in the unicast
	209	* table so in order to display the correct PfxRcd value
	210	* we must look at SAFI_UNICAST
	211	*/
	212	pfx_rcd_safi = (safi == SAFI_LABELED_UNICAST)
	213	? SAFI_UNICAST
	214	: safi;
	215
	216	table = bgp->rib[afi][pfx_rcd_safi];
	217	if (!table)
	218	continue;
	219
7f7940e6 MK	220	filter = &peer->filter[afi][safi];
7f7940e6 MK	221
c385f82a MK	222	if (!filter->advmap.aname \|\| !filter->advmap.cname
	223	\|\| !filter->advmap.amap \|\| !filter->advmap.cmap)
	224	continue;
	225
	226	if (!peer->advmap_config_change[afi][safi]
	227	&& !peer->advmap_table_change)
7f7940e6 MK	228	continue;
7f7940e6 MK	229
e73c112e MK	230	if (BGP_DEBUG(update, UPDATE_OUT)) {
	231	if (peer->advmap_table_change)
	232	zlog_debug(
	233	"%s: %s - routes changed in BGP table.",
	234	__func__, peer->host);
	235	if (peer->advmap_config_change[afi][safi])
	236	zlog_debug(
	237	"%s: %s for %s - advertise/condition map configuration is changed.",
	238	__func__, peer->host,
	239	get_afi_safi_str(afi, safi,
	240	false));
	241	}
	242
7f7940e6 MK	243	/* cmap (route-map attached to exist-map or
	244	* non-exist-map) map validation
	245	*/
c385f82a MK	246	ret = bgp_check_rmap_prefixes_in_bgp_table(
c385f82a MK	247	table, filter->advmap.cmap);
7f7940e6 MK	248
	249	/* Derive conditional advertisement status from
	250	* condition and return value of condition-map
	251	* validation.
	252	*/
c385f82a	253	if (filter->advmap.condition == CONDITION_EXIST)
fa36596c	254	filter->advmap.update_type =
c385f82a MK	255	(ret == RMAP_PERMITMATCH) ? ADVERTISE
	256	: WITHDRAW;
	257	else
fa36596c	258	filter->advmap.update_type =
c385f82a MK	259	(ret == RMAP_PERMITMATCH) ? WITHDRAW
c385f82a MK	260	: ADVERTISE;
7f7940e6	261
c5aec50b MK	262	/* Send regular update as per the existing policy.
	263	* There is a change in route-map, match-rule, ACLs,
	264	* or route-map filter configuration on the same peer.
	265	*/
c385f82a	266	if (peer->advmap_config_change[afi][safi]) {
e73c112e MK	267
	268	if (BGP_DEBUG(update, UPDATE_OUT))
	269	zlog_debug(
	270	"%s: Configuration is changed on peer %s for %s, send the normal update first.",
	271	__func__, peer->host,
	272	get_afi_safi_str(afi, safi,
	273	false));
	274
7f7940e6 MK	275	paf = peer_af_find(peer, afi, safi);
	276	if (paf) {
	277	update_subgroup_split_peer(paf, NULL);
	278	subgrp = paf->subgroup;
	279	if (subgrp && subgrp->update_group)
	280	subgroup_announce_table(
	281	paf->subgroup, NULL);
	282	}
c385f82a	283	peer->advmap_config_change[afi][safi] = false;
7f7940e6	284	}
c5aec50b MK	285
c5aec50b MK	286	/* Send update as per the conditional advertisement */
c385f82a MK	287	bgp_conditional_adv_routes(peer, afi, safi, table,
c385f82a MK	288	filter->advmap.amap,
fa36596c	289	filter->advmap.update_type);
7f7940e6	290	}
c385f82a	291	peer->advmap_table_change = false;
7f7940e6 MK	292	}
	293	return 0;
	294	}
	295
	296	void bgp_conditional_adv_enable(struct peer *peer, afi_t afi, safi_t safi)
	297	{
	298	struct bgp *bgp = peer->bgp;
	299
	300	assert(bgp);
	301
	302	/* This flag is used to monitor conditional routes status in BGP table,
	303	* and advertise/withdraw routes only when there is a change in BGP
	304	* table w.r.t conditional routes
	305	*/
c385f82a	306	peer->advmap_config_change[afi][safi] = true;
7f7940e6 MK	307
	308	/* advertise-map is already configured on atleast one of its
	309	* neighbors (AFI/SAFI). So just increment the counter.
	310	*/
e73c112e MK	311	if (++bgp->condition_filter_count > 1) {
	312	if (BGP_DEBUG(update, UPDATE_OUT))
	313	zlog_debug("%s: condition_filter_count %d", __func__,
	314	bgp->condition_filter_count);
	315
7f7940e6	316	return;
e73c112e	317	}
7f7940e6 MK	318
	319	/* Register for conditional routes polling timer */
	320	thread_add_timer(bm->master, bgp_conditional_adv_timer, bgp,
	321	CONDITIONAL_ROUTES_POLL_TIME, &bgp->t_condition_check);
	322	}
	323
	324	void bgp_conditional_adv_disable(struct peer *peer, afi_t afi, safi_t safi)
	325	{
	326	struct bgp *bgp = peer->bgp;
	327
	328	assert(bgp);
	329
	330	/* advertise-map is not configured on any of its neighbors or
	331	* it is configured on more than one neighbor(AFI/SAFI).
	332	* So there's nothing to do except decrementing the counter.
	333	*/
e73c112e MK	334	if (--bgp->condition_filter_count != 0) {
	335	if (BGP_DEBUG(update, UPDATE_OUT))
	336	zlog_debug("%s: condition_filter_count %d", __func__,
	337	bgp->condition_filter_count);
	338
7f7940e6	339	return;
e73c112e	340	}
7f7940e6 MK	341
	342	/* Last filter removed. So cancel conditional routes polling thread. */
	343	THREAD_OFF(bgp->t_condition_check);
	344	}